Influence of collision on the flow through in-vitro rigid models of the vocal folds

Deverge, Mickaël; Pelorson, Xavier; Vilain, CE; Lagrée, Pierre‐Yves; Chentouf, FZ; Willems, Jfh Jan; Hirschberg, Avraham

doi:10.1121/1.1625933

Cited by 56 publications

(66 citation statements)

References 17 publications

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“…During this period, U ⌬p and U wall are in phase and U wall may become higher than U ⌬p , which could explain the considerable unsteadiness of the flow at this fraction of the duty cycle. This phenomenon has been reported by Deverge et al 45 in the case of experiments involving prototypes of the human glottis. In their observations, however, the effect of U wall seems to be more evident in channels with constant height.…”

Section: A General Resultssupporting

confidence: 75%

Numerical simulations of fluid-structure interactions in single-reed mouthpieces

Silva

Scavone

Walstijn

2007

The Journal of the Acoustical Society of America

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Most single-reed woodwind instrument models rely on a quasistationary approximation to describe the relationship between the volume flow and the pressure difference across the reed channel. Semiempirical models based on the quasistationary approximation are very useful in explaining the fundamental characteristics of this family of instruments such as self-sustained oscillations and threshold of blowing pressure. However, they fail at explaining more complex phenomena associated with the fluid-structure interaction during dynamic flow regimes, such as the transient and steady-state behavior of the system as a function of the mouthpiece geometry. Previous studies have discussed the accuracy of the quasistationary approximation but the amount of literature on the subject is sparse, mainly due to the difficulties involved in the measurement of dynamic flows in channels with an oscillating reed. In this paper, a numerical technique based on the lattice Boltzmann method and a finite difference scheme is proposed in order to investigate the characteristics of fully coupled fluid-structure interaction in single-reed mouthpieces with different channel configurations. Results obtained for a stationary simulation with a static reed agree very well with those predicted by the literature based on the quasistationary approximation. However, simulations carried out for a dynamic regime with an oscillating reed show that the phenomenon associated with flow detachment and reattachment diverges considerably from the theoretical assumptions. Furthermore, in the case of long reed channels, the results obtained for the vena contracta factor are in significant disagreement with those predicted by theory. For short channels, the assumption of constant vena contracta was found to be valid for only 40% of the duty cycle.

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Section: A General Resultssupporting

confidence: 75%

Numerical simulations of fluid-structure interactions in single-reed mouthpieces

Silva

Scavone

Walstijn

2007

The Journal of the Acoustical Society of America

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“…We did not design a model with rigid vocal folds (e.g. Deverge et al, 2003;Hofmans et al, 2003), which would not allow the study of amplitude and frequency modulation. Furthermore, in contrast to mathematical models, it is virtually impossible to avoid slight asymmetries [e.g.…”

Section: Materials and Methods The Mechanical Syrinx Model (Msm)mentioning

confidence: 99%

Amplitude and frequency modulation control of sound production in a mechanical model of the avian syrinx

Elemans

Müller

Larsen

et al. 2009

Journal of Experimental Biology

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SUMMARYBirdsong has developed into one of the important models for motor control of learned behaviour and shows many parallels with speech acquisition in humans. However, there are several experimental limitations to studying the vocal organ -the syrinx -in vivo. The multidisciplinary approach of combining experimental data and mathematical modelling has greatly improved the understanding of neural control and peripheral motor dynamics of sound generation in birds. Here, we present a simple mechanical model of the syrinx that facilitates detailed study of vibrations and sound production. Our model resembles the 'starling resistor', a collapsible tube model, and consists of a tube with a single membrane in its casing, suspended in an external pressure chamber and driven by various pressure patterns. With this design, we can separately control 'bronchial' pressure and tension in the oscillating membrane and generate a wide variety of 'syllables' with simple sweeps of the control parameters. We show that the membrane exhibits high frequency, self-sustained oscillations in the audio range (>600 Hz fundamental frequency) using laser Doppler vibrometry, and systematically explore the conditions for sound production of the model in its control space. The fundamental frequency of the sound increases with tension in three membranes with different stiffness and mass. The lowerbound fundamental frequency increases with membrane mass. The membrane vibrations are strongly coupled to the resonance properties of the distal tube, most likely because of its reflective properties to sound waves. Our model is a gross simplification of the complex morphology found in birds, and more closely resembles mathematical models of the syrinx. Our results confirm several assumptions underlying existing mathematical models in a complex geometry.

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“…This shows that, in general, the Bernoulli equation fails to produce accurate estimations of flows through the threedimensional glottis. More accurate analytic models exist, 14,34 but they are less intuitive than the Bernoulli equation, and applicable only to two-dimensional ͑rectangular͒ geometries.…”

Section: Convergent 10°uniformmentioning

confidence: 99%

Intraglottal pressures in a three-dimensional model with a non-rectangular glottal shape

Scherer

Torkaman

Kucinschi

et al. 2010

The Journal of the Acoustical Society of America

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This study used a symmetric, three-dimensional, physical model of the larynx called M6 in which the transverse plane of the glottis is formed by sinusoidal arcs for each medial vocal fold surface, creating a maximum glottal width of 0.16 cm at the location of the minimal glottal area. Three glottal angles were studied: convergent 10°, uniform ͑0°͒, and divergent 10°. Fourteen pressure taps were incorporated in the upstream-downstream direction on the vocal fold surface at three coronal locations, at the one-fourth, one-half, and three-fourths distances in the anterior-posterior direction of the glottis. The computational software FLUENT was used to compare and augment the data for these cases. Near the glottal entrance, the pressures were similar across the three locations for the uniform case; however, for the convergent case the middle pressure distribution was lower by 4% of the transglottal pressure, and lower by about 2% for the divergent case. Also, there were significant secondary velocities toward the center from both the anterior commissure and vocal process regions ͑of as much as approximately 10% of the axial velocities͒. Thus, the three dimensionality created relatively small pressure gradients and significant secondary velocities anteriorly-posteriorly within the glottis.

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Influence of collision on the flow through in-vitro rigid models of the vocal folds

Cited by 56 publications

References 17 publications

Numerical simulations of fluid-structure interactions in single-reed mouthpieces

Numerical simulations of fluid-structure interactions in single-reed mouthpieces

Amplitude and frequency modulation control of sound production in a mechanical model of the avian syrinx

Intraglottal pressures in a three-dimensional model with a non-rectangular glottal shape

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